A study of lap dancers provides the best evidence yet that women send out hidden signals to let men know they are fertile.

Dancers who are "on heat" receive more tips from admiring men than those on the Pill or in the non-fertile periods of their menstrual cycle, researchers found.

The study, conducted by US scientists at the University of New Mexico, suggests that women somehow advertise their fertility during oestrus.

Experts suspect that pheromones - subtle scent signals that in animals play a key role in sexual attractiveness - may be involved. In other words, fertile women smell more appealing to men. Changes in behaviour and appearance may also be important.

The researchers, led by psychologist Dr Geoffrey Miller, compared the earnings of lap dancers who were menstruating naturally with others taking the contraceptive pill.

During the non-fertile periods of their menstrual cycle, dancers not on the Pill earned much the same as those using the contraceptive.

But when the naturally cycling dancers entered their fertile period, their tips became significantly more generous.

The evidence was the first to show that oestrus has a "real effect on women's earnings", Dr Miller told New Scientist magazine.

However, even on non-fertile days, lap dancers with natural menstrual cycles earned quite well, demonstrating that fertility was not all that the men in their audience were interested in.

"Previous research has shown that women's faces, scent and clothing become more attractive in oestrus," said Dr Miller.

http://www.channel4.com/news/articles/society/health/lap+dancers+reveal+fertility+hints/904547 [Links inactive - To make links active and clickable, login or click here to register]

Poor science I think, how do they know that it's not that the "wrong time of the month" makes them poor dancers?Perhaps someone should think this through and repeat the experiment properly.Any volunteers?